Different Types Of Operations Research Articles

Optimization of fourth order Sturm-Liouville type differential inclusions with initial point constraints

<p style='text-indent:20px;'>The present paper studies a new class of problems of optimal control theory with differential inclusions described by fourth order Sturm-Liouville type differential operators (SLDOs). Then, there arises a rather complicated problem with simultaneous determination of the SLDOs with variable coefficients and a Mayer functional depending of high order derivatives of searched functions. The sufficient conditions, containing both the Euler-Lagrange and Hamiltonian type inclusions and "transversality" conditions are derived. Formulation of the transversality conditions at the endpoints <inline-formula><tex-math id="M1">\begin{document}$t = 0$\end{document}</tex-math></inline-formula> and <inline-formula><tex-math id="M2">\begin{document}$t = 1$\end{document}</tex-math></inline-formula> of the considered time interval plays a substantial role in the next investigations without which it is hardly ever possible to get any optimality conditions. The main idea of the proof of optimality conditions of Mayer problem for differential inclusions with fourth order SLDO is the use of locally-adjoint mappings. The method is demonstrated in detail as an example for the semilinear optimal control problem, for which the Weierstrass-Pontryagin maximum principle is obtained.

Derivatives of the Shape Operator of Real Hypersurfaces in the Complex Quadric

On a real hypersurface in the complex quadric we can consider the Levi-Civita connection and, for any nonnull constant k, the k-th generalized Tanaka-Webster connection. We also have a differential operator of first order of Lie type associated to the k-th generalized Tanaka-Webster connection. We prove non-existence of real hypersurfaces in the complex quadric for which the covariant derivatives associated to both connections coincide or Lie derivative and Lie type differential operator coincide when they act on the shape operator of the real hypersurface.

Qualitative model to enhance quality of metadata for data warehouse

A metadata quality directly impact on the decision making. Therefore, the metadata is enhanced with semantics to improve quality of metadata but no formal representation is laid down. Here in this work, the formal representation of metadata is proposed to enhance the quality of information required for decision making. Therefore, in this paper three formal models are defined to properly manage metadata with different types of operation and to provide qualitative information to user. First is to define the metadata. Second is to describe metadata development process. Third model is used to formally describe the complete process of metadata management. All three models are used to properly representation and management of metadata.

On the positive semigroups generated by Fleming-Viot type differential operators

In this paper we study a class of degenerate second-order elliptic differential operators, often referred to as Fleming-Viot type operators, in the framework of function spaces defined on the \begin{document}$d$\end{document} -dimensional hypercube \begin{document}$Q_d$\end{document} of \begin{document}$\mathbf{R}^d$\end{document} , \begin{document}$d ≥1$\end{document} . By making mainly use of techniques arising from approximation theory, we show that their closures generate positive semigroups both in the space of all continuous functions and in weighted \begin{document}$L^{p}$\end{document} -spaces. In addition, we show that the semigroups are approximated by iterates of certain polynomial type positive linear operators, which we introduce and study in this paper and which generalize the Bernstein-Durrmeyer operators with Jacobi weights on \begin{document}$[0, 1]$\end{document} . As a consequence, after determining the unique invariant measure for the approximating operators and for the semigroups, we establish some of their regularity properties along with their asymptotic behaviours.

The Economics of Waste Recycling in Iraq: Wasted Resources and Lost Opportunities

Abstract The issue of remediation and recycling wastes in contemporary civilization is of a paramount importance economically, this is because the human leaves behind him a huge amount of waste in various types through his consumption and his daily life practices and these wastes are handled incorrectly around the world. This has led to the destruction of many components of the environment as well as the tremendous waste of available resources in the recycling and re-processing operations of different types of wastes, such as reuse it as raw materials again or reuse it in production of electric power through flammable types. In Iraq, especially after 2003, this problem takes serious trends, with increasing human consumption and with great economic openness, which led to a complex problem through pollution of the environment, waste of resources and lack of vision and mechanisms to deal with the huge quantities of waste and inability of the private sector to contribute in solving this problem as it fits with the size of the daily flow of inhabitants of large and small cities, as well as inhabitants of the suburbs and countryside. As this requires a clear path to activate the business sector related to recycling in an integrated way with other economic sectors, and this is can be done through backward and forward connections by creating an economic sector with the participation of governmental and private efforts that rise to the scale of the problem and find the correct way to the proper solution to this economic path in a way that provides opportunities and invests resources and limit their waste.

Role of Magnetic Resonance Imaging in evaluation of postoperative knee surgery

Background: MRI has high sensitivity and specificity regarding the assessment of the post-operative knee joint. Purpose: to assess the role of MRI in evaluation of the post-operative knee joint and assessment of the post complications after ACL, meniscal and cartilage surgical repair procedures. Patients and Methods: this study included 20 patients, their age range between 14-50 years, all presented postoperative knee were referred to Radiology Department at El-Hussien University Hospital and private centers for MRI exam for post-operative assessment, complication or follow up after orthopedic examination from Orthopedic Department at El-Hussien Hospitals and Outpatient Clinic. Patients had MRI imaging of the affected knee joint using high field strength scanners (1.5 T) MRI unit (Achieva, Philips medical system) MRI was performed by Knee coil in all cases. Results: this study included 15(75%) males and 5 females (5%)(A) Due to different types of operations 10(50%) had ACL reconstruction,6(30%) had menisectomy,4(20%) had cartilage repair. (B) Due to causes16(80%) trumatic,4(20%)non trumatic. (C) Due to types of complications: 3(15%) had no complications,12(60%)had swelling, 2(10%) had limitation of movement,2(10%) had pain and limitation,1(5%)had pain and swelling. Conclusion: MRI proved as an accurate method for evaluation of the knee joint after ACL, meniscus and cartilage repair that can help predict post-operative complications.

Pattern of abdominal wall hernia attended in Fishtail Hospital, Pokhara, Nepal

Introduction: All hernias are caused by a combination of pressure and an opening or weakness of muscle or fascia. The pressures push an organ or tissue through the opening or weak spot. Sometimes muscle weakness is present at birth; more often it occurs later in life. Abdominal wall hernias occur only at sites at which the aponeurosis and fascia are not covered by striated muscle. The aim of the study was to know different pattern of abdominal hernias, to analyze various clonal and demographic profiles of various abdominal wall hernias presenting to the mid-western part of Nepal and to evaluate different types of operation and complication performed in hernias patients.&#x0D; Methods: Hospital based retrospective descriptive study performed in Fishtail Hospital and Research Centre, Pokhara Nepal in October 2012 to July 2017. Ethical clearance was taken from institute and written consent was taken from all the patients who are involved in the study. All sociodemographic data were collected and analyzed by using SPSS 20 statistical software.&#x0D; Results: In this study period, 492 patients of various types of hernias were operated by various methods. Most common type of hernia is indirect inguinal hernia (94.39%) and one rare spigelian hernia was also there. Right inguinal hernia was more common (58.42%).&#x0D; Conclusion: Inguinal Hernia was the commonest type of hernia (394, 90.3%). Among inguinal hernia right side was more common (58.42%). Among inguinal hernias, most of the hernias were found in 0-9 years (38.21%). In this study we found recurrence rate 1.4%.

A Review on the Critical Success Factors (CSFs) in the Operation of Hotels

Abstract: Critical Success Factors (CSFs) have been recognized as an important and powerful approach for the competitiveness and success of the hospitality organizations in particular hotels in the tourism industry. The implementation of some core capabilities, activities, and facilities may provide better opportunities for the hoteliers to be successful in the intensive marketplace. This article studies the CSFs for the hotels’ operation in the past studies. To do this, the hotel-related CSFs for operation of different types of hotels were first compiled through the review literature. Then, the main issues, gaps, and conditions of the studies have been considered. Further studies are also suggested based on the identified gaps in the reviewed literature.

Modularly weighted four dimensional matrix summability with application to Korovkin type approximation theorem

This work is concerned with various weighted four dimensional matrix summability methods in modular function spaces associating with generalized difference operator involving (p,q)-gamma function. Following very recent results of Kadak (2017) [20], we first introduce a new type of difference operator on double function sequences and, also define modularly weighted A-statistical convergence and modularly statistically N˜A-summability by means of weighted four dimensional regular matrix A. We also present some important inclusion relations between newly proposed summability methods. Moreover, based on the concept of modularly statistically N˜A-summability, we prove a Korovkin type approximation theorem for functions of two variables in modular spaces. Finally, in order to show that our proposed method and its applications to approximation results are stronger than the existing methods, we display an illustrative example using bivariate (p,q)-Bernstein Kantorovich operators.

Polynomials whose coefficients coincide with their zeros

In this paper we consider monic polynomials such that their coefficients coincide with their zeros. These polynomials were first introduced by S. Ulam. We combine methods of algebraic geometry and dynamical systems to prove several results. We obtain estimates on the number of Ulam polynomials of degree N. We provide additional methods to obtain algebraic identities satisfied by the zeros of Ulam polynomials, beyond the straightforward comparison of their zeros and coefficients. To address the question about the existence of orthogonal Ulam polynomial sequences, we show that the only Ulam polynomial eigenfunctions of hypergeometric type differential operators are the trivial Ulam polynomials $$\{x^N\}_{N=0}^\infty $$ . We propose a family of solvable N-body problems such that their stable equilibria are the zeros of certain Ulam polynomials.

Posterior urethroplasty: indications and results, a six years’ experience from two teaching hospitals in Iraq

Background: Posterior urethral strictures remain an everyday challenge in urological practice. Different types of operations to repair the stricture have different outcome concerning re-establishment of the urethral function and anatomy. Posterior urethroplasty is one of the frequently chosen operations. The aim of this study is to reveal indications, results and complications of posterior urethroplasty performed on fifteen patients with long posterior urethral strictures in a major urological center.Methods: Fifteen male patients have undergone anastomotic perineal urethroplasty for long posterior urethral strictures in the period from September 2010 to August 2016. The patients age ranged between 12-42 years (mean =28). They were referred to Al-Karama urological center from emergency hospitals, and Al-Hussain teaching hospital came to medical consultation to the center with established strictures. They were evaluated thoroughly pre-operatively with cystogram and retrograde urethrogram (RUGs).Results: Success rate was 66.7%. The follow-up period was short, no patient needed re-operation. Most had normal caliber urinary stream and required no optical urethroplasty or dilation. Failure noticed in two patients, one of them developed impotence post-operatively.Conclusions: The study concludes that open perineal urethroplasty remains the gold standard for the management of long posterior urethral strictures.

Identifying treatment schemes for fruit and vegetable wash-water

The fresh-cut fruit and vegetable sector continues to expand as consumers are looking for fresh yet convenient ready-to-eat foods. The driving force behind this increase is the many health benefits that researchers continue to report for fruits and vegetables. Investigations have shown that the processing of fresh-cut fruits and vegetables generates about 5 L of wastewater (wash-water) per kg of produce, whether it is fruit, leafy greens or root vegetables. This wash-water requires treatment prior to disposal or recycling. Generic water treatment units are too expensive for most small to medium sized operations, which require more affordable technologies. Even though there are a variety of treatment technologies available, the challenge for producers and regulators is that the selection of the appropriate treatment technology is difficult, and tools are needed to help make the decisions. Data for the research was collected by collecting samples from two different types of operation, washing and washing and processing. Various bench scale treatment processes where then tested, including settling, coagulation and flocculation with settling, centrifuge, dissolved air flotation, electrocoagulation, screening and hydrocyclone. The decisions tools developed decision matrices to summarize the removal effectiveness of the different treatments for typical wastewater parameters and serve as a reference tool in understanding wash-water treatment technologies and their effectiveness in treating various wash-waters. The data was then further analyzed to develop predictive correlations for raw wash-waters, followed by the development of models that identified which treatment process worked best for the type of wash-water being handled. Combining the decision matrices, correlations, and models also show the potential for water reuse. For example, wash-water high in suspended solids can be treated by electrocoagulation and settling. The tools provide information that growers, government and consultants can use in determining treatment options that were not previously available or studied in literature.

飞秒激光辅助白内障超声乳化术后角膜内皮的改变

目的：探讨飞秒激光辅助白内障超声乳化术与超声乳化术治疗白内障对角膜内皮的影响，分析比较两种手术方式术后角膜内皮细胞的改变特点。方法：分析我院2017年1月~2018年1月收治的白内障患者86例(100眼)，其中A组46例(50眼)行飞秒激光辅助白内障超声乳化术，B组40例(50眼)行白内障超声乳化术，用角膜内皮镜分别观察患者术前、术后1周、术后1个月、术后3个月的中央区角膜内皮细胞密度、六角形细胞比例、平均细胞面积及角膜内皮丢失率。结果：术后两组中央区角膜内皮细胞密度和六角形细胞比例均较术前降低，平均细胞面积较术前增大；两组术后1周、术后1个月、术后3个月的中央区角膜内皮细胞密度、六角形细胞比例、平均细胞面积与术前相比差异有统计学意义(P < 0.05)，术后相同时间点平均细胞面积及角膜内皮丢失率B组均大于A组、六角形细胞比例B组均小于A组，差异有统计学意义(P < 0.05)。结论：飞秒激光辅助白内障超声乳化术对角膜内皮的损伤更小，是一种较为安全的手术方式。 Objective: To evaluate the efficacy of corneal endothelial cell after femtosecond laser-assisted cataract surgery and conventional phacoemulsification cataract surgery, and compare the changes after two cataract surgery. Methods: Clinical data in our hospital from January 2017 to January 2018, which treated 86 cases (100 eyes) of cataract patients, were divided into two groups according to different types of operation. A group includes 46 cases (50 eyes), underwent femtosecond laser assisted cataract surgery; in the B group, 40 cases (50 eyes), underwent the conventional phacoemulsification cataract surgery. Corneal endothelial cell density, mean cell area, proportion of hexagonal cells and cell loss rate were observed preoperatively and 1 week, 1 month, 3 months postoperatively for the two groups. Results: After the operation, the endothelial cell density and the proportion of hexagonal cells of the two groups all decreased, and mean cell area increased. The difference of corneal endothelial cell density, mean cell area, proportion of hexagonal cells, between before and after operation, was statistically significant, in the same time after operation, cell loss rate in group B was bigger than those in group A, the proportion of hexagonal cells in group B was smaller than those in group A. Conclusions: Femtosecond laser-assisted cataract surgery has a lower damage to corneal endothelial cell, and was a safe operation method.

On bipolar fuzzy soft graphs

In this paper, we combine the concepts of bipolar fuzzy soft sets and graph theory. Then we introduce notations of bipolar fuzzy soft graph and strong bipolar fuzzy soft graph. We also present several different types of operations including cartesian product, strong product and composition on bipolar fuzzy soft graphs and investigate some properties of them.

Procedure-Specific Trends in Surgical Outcomes

Quality improvement efforts have generally focused on hospital benchmarking, and processes and outcomes shared among all operations. However, quality improvement could be inconsistent across different types of operations. The objective of this study was to identify operations needing additional concerted quality improvement efforts by examining their outcomes trends. Ten procedures (colectomy, esophagectomy, hepatectomy, hysterectomy, pancreatectomy, proctectomy, total hip arthroplasty, total knee arthroplasty, thyroidectomy, and ventral hernia repair) commonly accrued into the American College of Surgeons NSQIP between 2008 and 2015 were included. Trends in risk-adjusted, standardized, smoothed rates were constructed for each procedure across 6 outcomes (mortality, pneumonia, renal failure, surgical site infection, unplanned intubation, and urinary tract infection [UTI]). Of 1,255,575 operations analyzed, the overall unadjusted rate for mortality across all 10 procedures was 1.08%, for pneumonia 1.44%, for renal failure 0.67%, for surgical site infection 5.28%, for unplanned intubation 1.11%, and for UTI 1.86%. Hepatectomy demonstrated the greatest improvement across outcomes (4 of 6 outcomes; 362 adverse events avoided out of 10,000 procedures), and UTI demonstrated the greatest improvement across procedures (8 of 10 procedures; 989 adverse events avoided out of 10,000). For pancreatectomy, rates of mortality, unplanned intubation, and UTI improved, but surgical site infection rates were detected to have significantly increased (p < 0.05). Hepatectomy was detected to have improved across the greatest number of outcomes, and UTI rates improved significantly across the greatest number of procedures. Surgical site infection rates after pancreatectomy, however, were detected to have increased, identifying an urgent need for additional concerted quality improvement efforts.

Time-resolved deposition in the remote region of the JET-ILW divertor: measurements and modelling

One crucial requirement for the development of fusion power is to know where, and how much, impurities collect in the machine, and how much of the fuelling isotope tritium will be trapped therein. The most relevant information on this issue comes from the operation of the Joint European Tokamak (JET), which is the world’s largest operating tokamak and has the same interior plasma-facing materials as the next step machine, ITER. Much of the information gained so far has been from post-mortem analysis of samples collected after whole campaigns involving varied types of operation. This paper describes time-resolved measurements of the deposition rate using rotating collectors (RC) placed in remote areas of the JET divertor during the 2013–2014 campaign with the ITER-like Wall (ILW). These techniques allow the effects of different types of operation to be distinguished. Rotating collectors made of silicon discs housed behind an aperture are exposed to the plasma. Each time the magnetic field coils are ramped up for a discharge the disc rotates, providing a linear relationship between the exposed region and the discharge number. Post-mortem ion beam analyses provide information on the deposit composition as a function of the discharge number. The results show that the Be deposition average for the RC in the corners of the inner and outer divertor are 4.9 × 1016 cm−2 and 1.8 × 1017 cm−2, respectively, accumulated over an average of ∼25 pulses. Data from the rotating collector below Tile 5 in the central region of divertor indicate a Be deposition rate of 9.3 × 1015 cm−2, per ∼25 pulses.

Optimizing multiship routing and scheduling with constraints on inventory levels in a Brazilian oil company

AbstractThis study addresses a real‐life multiship routing and scheduling application with inventory constraints that arises in pickup and delivery operations of different types of crude oil from various offshore oil rigs (platforms) to coastal terminals. Oil transportation largely results from the need to maintain inventories at each supply point (platform) between minimum and maximum levels, considering production rates in these operational points, and to meet demands of different oils in the terminals within the planning time horizon. Routing and scheduling of the available fleet aims to obtain solutions of minimum total costs, subject to various constraints such as the maximum volume of cargo carried on each ship, simultaneous cargo unloading in some terminals, conditions that rule ship docking in offshore platforms and terminal berths, among others. In this research, we modify and extend inventory constrained maritime routing and scheduling models to appropriately represent the problem of a case study at a Brazilian company and to solve small‐to‐moderate instances based on real data. We also present a matheuristic to deal with larger problem instances. Solution evaluation by company experts indicates that the model and this hybrid heuristic properly represent the problem and highlights the potential of their application in practice.

Post-Operative Restlessness During Recovery Period Following General Anaesthesia

Background: Smooth induction and smooth maintenance, smooth reversal and quite recovery is a key word in general anaesthesia. All anaesthetist desires that his patients wake-up smoothly &amp; quietly. However the matter is not easy at all. Anaesthetist often faces a bitter experiences &amp; awk.ward situation during recovery from anaesthesia. Objective: To detect the degree &amp; frequency of restlessness in various types of patients of different age &amp; sex groups and in different types of operations.Methodology &amp; Materials : Our study was carried out in North Bengal Medical College Hospital, Sirajgonj, in between July/2014 &amp; December/2014. 60 (sixty) patients were chosen of different age &amp; sex group and of different types of operation for this perpous.Results: Our study shows that the patients of E.N.T. surgery &amp; the patients of Paediatric surgery, were most vulnerable &amp; responded badly, during reversal and in the post operative ward. Among others a few of them developed restlessness due to some other cause. The children were more prone to develop restlessness than the adults. The Orthopaedic surgery patients also responded badly during recovery period.Conclusion: Special attention should given to this matter as it is really a hazardous situation to all; (i.e. anaesthetist, surgeon, O.T. Sister). An adequate pre-medication,smooth induction, quiet maintenance, smooth reversal &amp; a suitable post operative analgesic is absolutely necessary. Pre anesthetic visit &amp; close rapport with the patient is also essential to overcome this situation.KYAMC Journal Vol. 6, No.-2, Jan 2016, Page 645-648

Unearthing the creative thinking process: Fresh insights from a think-aloud study of garden design.

A number of theories of creativity have converged on the idea that creative thinking entails shifting between different processes. We attempt to build on recent theoretical developments through empirical work to examine creativity in the everyday environment of a garden designer. We asked designers with different levels of expertise, a matched group of fine artists and a non-designer, non-artist control group to work on a garden design. We asked them to ‘think aloud’ as they designed and we recorded audio and video. We coded resultant verbal segments as indicating the operation of different types of underlying thinking process identified in recent theoretical work. We then mapped these segments to the video of the designs and conducted Markov chain analysis to explore how thinking processes shifted as the design evolved. Finally, we examined the extent to which different types of thinking process shifts predicted the creativity of the final garden designs as determined by experts. We found that shifts between associative and analytic thinking processes predicted design creativity, but only when the operation of these two processes were tightly coupled in time. The positive association between shifting and creativity was strongest when analytic thinking processed affective content. These types of shifting were also elevated at times when a subset of participants switched between working on different designs; a strategy that positively predicted design creativity. Findings suggest expansion of mode shifting theories of creative thinking to include the importance of close coupling between different modes of thinking and of an analytic mode processing affective content.

Minimising work overload in mixed-model assembly lines with different types of operators: a case study from the truck industry

This paper considers the problem of sequencing mixed-model assembly lines (MMALs). Our goal is to determine the sequence of products to minimise work overload. This problem is known as the MMAL sequencing problem with work overload minimisation: we explicitly use task operation times to find the product sequence. This paper is based on an industrial case study of a truck assembly line. In this industrial context, as a reaction to work overloads, operators at the workstations finish their tasks before the product reaches the next workstation, but at the expense of fatigue. Furthermore, there are different types of operators, each with different task responsibilities. The originality of this work is to model this new way of reacting against work overloads, to integrate three operator types in the sequencing model and to apply the developed methods in a real industrial context. To solve this problem, we propose three meta-heuristic procedures: genetic algorithm, simulated annealing and a combination of these two meta-heuristics. All the methods proposed are tested on industrial data and compared to the solutions obtained using a mixed-integer linear programme. The results show that the proposed methods considerably improve the results of the current procedure used in the case study.